Bitfury 400 ghash not performing/failing

I have 10 of the bitfury 400 ghash units completely filled with all 16 h cards. These units are only putting out about 250 ghash each. These cards have never been great and unfortunately problematic and my worst asic purchase to date. They are pretty unstable considering they are just shy of a year old. My Burnin Avalon boards have been going strong for over 1.5 years and never had an issue beside replacing 2 fuses on them and replacing 1 capacitor. My boards have always had great airflow with big box fans over each setup along with full 80% + heatsink coverage on the entire board 2 weeks after purchase. Anyone else experiencing this same problem.

I need to figure out if the bitfury chips are dieing on the h cards which in turn prevents the 3 other cards in sequence on the m board not hash. Or if its an issue with the mboard itself. Being that all but maybe 1 complete setup is still hashing above 350 ghash I'm thinking it wouldn't be raspberry pi related or sd card related. I'm half temped to desolder all the pci express connectors and solder new pci express connectors on the m-boards. I'm thinking maybe over time with the slight wobble it has created intermittent contacts. Not sure but I find it hard to believe so many bitfury chips would fail this soon after just 1 year.

Anyone have any experience downclocking these things.